Df140 stalls at idle

[Marcel4t]

My 2004 JohnSuzki DF140 has developed a bad habit of stalling at idle, along with stalling when coming off throttle to neutral. Tends to happen after the motor has warmed up for a little bit. If I bump it up to about 2500 RPMs for a while and then drop back down, the fuel pump is loud. It is a new fuel pump. Is it safe to assume that the fuel pump is loud because It's low on gas in the VST? When it does shut down, one turn of the key and it starts right back up.
Some more information on what I've done to try to fix the problem:

Corroded plug on engine holder repaired.
I cleaned out the VST
Put in a new fuel pump New high pressure fuel filter
New low pressure fuel filter
New IAC
New primer bulb and quick connect

Anybody have any other ideas of what I could do to make this stop happening?
Is there something I should do since I installed a new IAC or is it just plug and play?

Thanks in advance!

[Moonlighter]

The other simple thing to do that can cause this is to remove the anti-syphon valve from your fuel tank. Its a well known issue that they fail and will restrict fuel flow at low rpm when the fuel volume is also low. So the engine starves. (Usually you then need to pump the primer bulb to get things going again)

Had this exact thing in a mates boat, we removed the AS valve from the tank (the outlet where the fuel hose attaches) and punched the ball, spring and seat out from the inside and reinstalled it as a straight through barb, and problem solved.

Even if this doesnt fix the problem, at least you have eliminated it as the cause and its a simple and inexpensive thing to do.

[Murray]

I believe there is a procedure for some IAC valves depending on your engine. I’ve read some post where members were talking about the procedure. If memory serves it’s the larger engines. My next post will be a web site that has pdf service manuals (genuine Suzuki) for $12US that will help you out. Sometimes links get blocked until the forum owners check it out, they may or may not allow it.

[Murray]

All one word s e l f f i x e r d o t c o m I have purchased a couple of service manuals and have had no issues

[Marcel4t]

All one word s e l f f i x e r d o t c o m I have purchased a couple of service manuals and have had no issues

I actually just googled Johnson DF 140 service manual and found it online for free. Thank you I'll give that a shot and see if setting the IAC works. I'll get back to you guys if it doesn't

[Marcel4t]

Okay so I adjusted the idle, I set it a little higher than the recommended 650 to 750, and it doesn't install as much but it still stalls.

[Murray]

Dig into that service manual for other high idle causes. Shifting in and out of gear at too high an idle could cause damage to the lower unit.

[ECU1984]

1) take the front airbox off and see if the screen that covers the throttle body throat is clogged
2) take cowl off and turn it upside down and feel way up under the rear air intake vent into the ductwork and see if clogged with leaves, bird nest or dirt dobber
3) while airbox is off, spray carb cleaner all around the throttle plate (butterfly valve) and see if it had a dirt lip built up around it. (causing it not to close completely)
I just had the exact same symptoms as you and the above items fixed mine after doing filters, injectors, IAC valve, vst, etc
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